Web feeding device for roll type driers



l! 5 7 44.1. FRANKLIN ,5 ,8

' m'm:nmc DEVICE .FOR ROLL ms DRIERS Filed my .18,- 1949 vz-sneet's-sheet 1 1950 J. J. FRANKLIN 2,517,861 ,IEB FEEDING DEVICE FORROLL TYPE nRIERs 7 Filed lay 18, 1949 -2 Sheds-Sheet 2 7 7 ilk 5/Patented- Aug. 8, i950 2,517,861 was FEEDING nnvrcn'roa' ROLL mi; nnmasJohn J. Franklin, Glenside, Pa., assignortolroctor & Schwartz, Inc.,Philadelphia, Pin, acorporation of Pennsylvania Application May 18,1949, Serial No. 93,934

- 8 Claims. -1

This invention relates to new and useful improvements in roll typedriers, and more particularly to driers for continuous web materialswherein the material is threaded back and forth vertically between andaround two vertically spaced sets or series of rolls and advancedthereby in one general direction.

In driers of this type the problem exists of effectively controllingtension in the web resulting in shrinkage of the material as it passesthrough the drier. It has been proposed to minimize tension in the webin roll type driers by providing a separate individual driving motor ofthe shaded-pole typeior each roll, and while this was a stepin the rightdirection it did not completely overcome the difficulty because onecharacteristic of this arrangement is that excess driving power existingin a motor toward the delivery end of the drier is added to the excesspower of the preceding driving motor cumulatively back to the feed endof the drier. This places the maximum tension on the material atthepoint where it contains the most moisture and is most subject tostretch. In the past this condition has been put up with due toinsufficient public interest in the shrinkproof properties of materials.However, in ,recent years the public has become quite shrinkproofminded, and it has become increasingly more important to eliminatestretch in a material during the process of drying.

With the foregoing in mind, one object of the present invention is toprovide a roll drier of the type described wherein tension in thematerial and resulting stretch thereof is substantially set forth anddescribed with reference to the acv companying drawings, in which:

, 2 lar to Fig. 3 but showing a modified form of the invention; and

Fig. 5 is a diagrammatic elevational view showing still anothermodification of the invention.

Referring now more particularly to the drawings, a roll drier of thetype to which the present invention pertains may comprise a housing iincluding a top 2 and oppositely disposed side and end walls 3 and 4,respectively.

Arranged within the housing longitudinally thereof is an upper series orset 01' rolls 5, SJ, 8, 9, l0 and II, and a lower series of similarrolls I2, 13,, l5, l6, l1 and [8, respectively. Each of these rollsisprovided with a shaft or trunnions which extend axially beyond the endsof the roll and project outwardly through suitable openings 2l in thehousing side walls 3 where they are rotatably mounted in suitablebearings IQ, for example, as shown in Fig. 2 of the drawing.

A continuous web a. enters the housing I I through an inlet opening 22therein and then outwardly of the housing I through a delivery opening23 at the opposite end of the housing from the inlet 22.

The path of travel of the web a: is defined by relatively transversepartitions 24 arran ed interiorly of the housing I and disposed adjacentthe several courses of the web in a manner subdividing the housing intoupper and lower chambers. Into these chambers air heated by sets ofcoils 25 is forced by pumps 26, the heated air ultimately dischargingthrough slots 24a in said partitions into contact with the traveling web3:.

According to the present invention the web 2:.

is withdrawn from the drier by means of a suitable pull-out roll 3|which is driven at a pre- Fig. 1 is a side elevational view, partiallysection, showing a roll type drier embodying the present invention;

Fig. 2 is a sectional view on line 2-2, Fig. 1;

Fig. 3 is a diagrammatic elevational view illustrating the invention andparticularly the control for the motor which drives the pull-out roll atthe delivery end of the drier; I

determined speed, and each of only the lower rolls l2, l3, ll, l5, l6,l1 and IS in the drier are driven at a surface speed faster than thesurface speed of the said pull-out roll 3|.

In the embodiment of the invention shown in Figs. 1 and 3 each of onlythe lower rolls l2, l3, ll, l5, l6, l1 and I8 is provided with aseparate individual and independent drive in the form of an electricmotor 21 which may drive its roll through a suitable speed reducingpulley and belt arrangement 28 of conventional type. Also, the web a: isfed into the housing I at a predetermined definite linear speed withrelation to the s n'faqe peed. of the lower series of rolls, forexelectric motor 32, for example, through a pulley and belt drive 33.

After passing between the quetch rolls 29 and 30 and before entering thedrier, the web :2: passes about a pair of idler r0115 '34 and and anintermediate compensator roll 35. The compensator roll 33 is mounted insuspended relation from a cable 31 which passes over a pulley 38 and hasa counterbalance weight 39 fixed to its other end. The counterweight 39is calibrated to cause the compensator roll 36 to rise and fallaccording to the slackness and tension, respectively, in the web at.

Connected to'the pulley 38 to rotate therewith is a smaller pulley 40which drives through a belt 4|, a pulley 42 that actuates a rheostat 43in the electric circuit of the motor 32 which drives the pull-out ro1l3|. The rheostat 43 is arranged so that in the event of slack in the weba: at the inlet to the drier the resulting upward movement or rise ofthe compensator roll 36 will operate the rheostat to speed up the motor32 and, conversely. in the event of increased tension on the web at 'theinlet causing the roll 36 to be drawn downwardly, the rheostat isoperated-to slow down the said motor 32, thereby synchronizing the speedof the pull-out roll 3| with the quetch rolls 29 and 30. 1

As previously pointed out, a particular requirement of the presentinvention is that each of the lower series of rolls be driven at asurface speed faster than the surface speed of the pull-out roll 3 I.This can be accomplished, for example, either by utilizing conventionaltype electric motors for individually driving the rolls of the lowerseries together with suitable mechanical devices to provide and maintainthe required surface speed of the rolls with relation to the rates offeed and delivery, respectively, of the web at, or by the use of lowpowered electric motors of the type known as single phase shaded-polemotors, which have a normal operating speed to drive therolls of thelower series at a surface speed faster than that of the pull-out roll3|.

Preferably, however, the motors 21 are of the shaded-pole type. Thesemotors are particularly adapted for use in the present instance becauseof certain characteristics of this type of motor which permits the motorto be stopped, as by overloading, for indefinite periods of time, withcurrent flowing through the motor windings, without the motor becomingoverheated or damaged. These same characteristics permit the motor to berestricted to any speed within its full range, from its maximum numberof revolutions per minute, when under minimum load, to zero or fullstop, under load, without harm, by variations occurring in the torqueload applied to the motor. The characteristics of this type of motoralso allow the motor to start under full load from a dead stop.

In operation of the drier in accordance with the present invention, thequetch rolls 29 and are driven at a predetermined fixed speed requiredto feed the web a: to the. drier at the desired rate, and each of therolls l2, l3, l4, l5, l6, l1 and I8 of the lower series is driven at asurface speed greater than that of the quetch rolls as previouslydescribed. Also, the speed of operation of the pull-out roll is lessthan the speed 9i il? S lower series of rolls.

the web a: at the roll l9 which decreases the pull.

4 By driving the pull-out roll at a slower speed than the lower seriesof rolls in the drier it will be apparent that there is a tendency toproduce slack in the web 2 between the pull-out roll 3| and the lastdrier roll I 3. 1 This produces slack in of the roll i8 on the web withthe result that a similar slack is produced at the preceding roll IT.This condition progresses from roll to roll of the bottom series thereofuntil a similar slack exists in the web a: at the first roll l2. Thisslack in the web at and ahead of the roll l2 allows the compensator roll36 to rise under the influence of the counterweight 39 so that therheostat 43 is operated to speed up the motor 32 and pull-out roll 3|which immediately corrects the slack condition between pull-out roll 3|and the last drier roll it, and so on, back through the drier.

The overall range of variation in the speed of the 'pull-out roll issmall and as it is speeded-up in the described manner the moderatelytaut condition of the web a: is re-established between pullout roll 3|and roll l8, and ultimately through the entire length of the fabric fromthe quetch rolls through the drier to said pull-out roll. Since therolls l2, l3, l4, l5, l6, "and II are each driven at a speed faster thanthe top speed of the pullout roll 3| it will be apparent that nosubstantial tension will be created in the web a: and what occurs isthat the web in the drier assumes a balanced substantially tensionlesscondition in which the lower series of rolls have just enough drivingpower to overcome the friction of the upper series of rolls and move theweb a: forward through the drier. The tension in the web a: at the inletend of the drier never exceeds the tension produced by the counterweight39 which, of course, can be determined to give any desired maximumtension in the web being dried.

It is not necessary to the present invention that a positive feed, suchas the quetch rolls 29 and 30, be employed to feed the web a: to thedrier, and the web may be drawn into the drier simply by the pullexerted thereon by the driven lower series of rolls in the drier. Thus,in the embodiment of the invention shown in Fig. 4 of the drawings theweb 3: is drawn from a small truck or other support 50 over a series ofidler rolls 5|, 52 and 53 and thence into the drier by the driven lowerseries of rolls l2, l3, l4, l5, I6, I! and I8, respectively. In passingfrom the idler 52 to the idler 53 the web 1: contacts a spreader bar 54which operates to remove wrinkles from the said web.

In the arrangement of Fig. 4 the pull-out roll 3| is driven at a fixedconstant speed from its motor 32 and, according to the presentinvention, each of only the lower series of rolls in the drier is drivenat a surface speed faster than the surface speed of the pull-out roll 3|In the embodiment illustrated, each of the lower rolls is provided witha separate individual and independent drive in the form of an electricmotor 21, preferably of the shaded-pole type, which may drive its rollthrough a pulley and belt arrangement 28 as aforesaid. I

In operation of this form of the invention, at the start the fasterspeed of the lower drier rolls tends to produce a slack condition in theweb :0 between the pull-out roll 3| and the last drier roll l9 whichdecreases the pull of the roll I 8 on the web with the result that asimilar slack is produced at the roll I! and so on back to the firstroll l2. The existence of a slack condition at the first roll l2 reducesthe pull on the web with the result that the speed of the web ismomentarily lessened until the web again is brought into driving'relationwith the first roll I2 and progressively through the drier toestablish, after a brief interval, a balanced substantially tensionlesscondition in which the lower series of drier rolls have just enoughdriving power to move the web x into and through the drier.

Another modification of the invention is shown in Fig. 5 of the drawingswherein, instead of providing separate drive means for the individuallower rolls of the drier as previously described, the lowerseries ofrolls l2, l3, ll, IS, I6, I! and I8 are driven mechanically from asingle power source. In the arrangement illustrated the lower series ofrolls are driven by a common or single chain or belt 55 which may bedriven, for example, from the pull-out motor '32, through a conventionaldrive arrangement 56. However, in this embodiment, as in the case ofthose previously described, it is essential that the surface speed ofthe lower drier rolls be faster than the surface speed of the pull-outroll 3|, and the operation of the drier will be as set forth herein.

From the foregoing description, it will be apparent that the presentinvention provides a roll drier wherein tension in material andresulting stretch thereof is substantially eliminated. The inventionfurther provides a substantially tension-free roll type drier which isautomatic in operation and entirely efilcient and foolproof in use.

While a particular embodiment of the present invention has beenillustrated and described herein it is not intended that the inventionbe limited to such disclosure and changes and modifications may be madetherein and thereto within the scope of the following claims.

I claim:

1. In a web-treating apparatus, upper and lower series of a plurality ofweb rolls around which a web is passed up and down and between thesucceeding rolls of each series, means to feed the web to said web rollsat a predetermined rate of speed, pull-out means operable to (raw theweb from the web rolls at a rate of speed controlled by variations intension in the web at the feed thereof, and drive means for the lowerseries only of said web rolls operable to drive each. of said lowerseries rolls at a surface speed greater than the rate of feed of the weband greater than the rate of withdrawal of the web by said pull-outmeans.

2. In a web-treating apparatus, upper and lower series of a plurality ofweb rolls around which a web is passed up and down and between thesucceeding rolls of each series, feed means for said web operable tofeed the web to the web rolls at a predetermined rate of speed, pull-outmeans operable to draw the web from said web rolls, variable speed drivemeans for said pull-out means controlled by variations in tension in theweb, and drive means for the lower series only of said web rollsoperable to drive each of said lower series rolls at a surface speedslightly greater than the rate of feed of the web by said feed means andgreater than the rate of withdrawal of the web by said pull-out means.

w 3. In a web-treating apparatus, upper and said web rolls, variablespeed drive means for said pull-out means, control means operable inresponse to variations in tension in the web between said feed means andfirst web roll to vary the speed of said pull-out means, and drivemeans, for the lower series only of said web rolls operable to driveeach of said lower series rolls at a surface speed slightly greater thanthe rate of feed of the web thereto by said feed means and greater thanthe rate of withdrawal of the web by said pull-out means.

4. In a web-treating apparatus, upper and lower series of a plurality ofweb rolls around which a web is passed upv and down and between thesucceeding rolls of each series, feed means operable to feed the web tothe first roll in said lower seriesat a predetermined rate of speed,pull-out means operable to di aw the web from the said web rolls,variable speed drive means for said pull-out means, a movablecompensator roll about which the web passes disposed between said feedmeans and the lower series of web rolls, control means actuable by saidcompensator roll in response to variations in tension in the weboperable to vary the speed of said pull-out means, and drive means forthe lower series only of said web rolls operable to drive each of saidlower series rolls at a surface speed slightly greater than the rate offeed of the web thereto by said feed means and greater than the rate ofwithdrawal of the web by said pull-out means.

5. In a web-treating apparatus, a housing, upper and lower series of aplurality of web rolls in said housing around which a web is passed upand down and between the succeeding rolls of each series, feed rollsadjacent one end of the housing operable to feed the web thereto and tothe web rolls at a, predetermined rate of speed, a pull-out rolladjacent the other end of the housing operable to draw the web from theseries of web rolls, means operable in response to variations in tensionin the web between the feed and web rolls operable to vary the speed ofsaid pull-out roll, and driving means for the lower series only of saidweb rolls operable to drive each of said lower series rolls at a surfacespeed slightly greater than the rate of feed of the web thereto by saidfeed rolls and greater than the rate of withdrawal of the web by saidpull-out roll.

6. In a web-treating apparatus, upper and lower series of a plurality ofweb rolls around which a web is passed up and down and between thesucceeding rolls of each series, feed rolls operable to feed the web tothe web rolls at a predetermined rate of speed, a pull-out roll operableto draw the web from the said web rolls, means between the feed and webrolls operable in response to variations in tension in the web operableto vary the speed of said pull-out roll, and a separate independentlyoperable driving means for each of the lower series only of said webrolls operable to drive each of said lower series rolls at a surfacespeed slightly greater than the rate of feed of the web thereto by saidfeed rolls and greater than the rate of withdrawal of the web by saidpull-out roll.

, 7. In a web-treating apparatus, upper and lower series of a pluralityof web rolls around which a web'is passed up and down and between thesucceeding rolls of each series, feed rolls operable to feed the web tothe web rolls at a predetermined rate of speed, a pull-out roll operableto draw the web from the web rolls, variable speed drive means for saidpull-out roll, a movable compensator roll-about which the web passesdisposed between said feed rolls and the web rolls, control meansactuable by said compensator roll in re- 7 spouse to variations intension in the web operableto vary the speed of said pull-out roll, and

driving means for the lower series only 01' said web rolls operable todrive each of said lower series rolls at a surface speedslightly greaterthan the rate of feed of'the web thereto'by said feed rolls and greaterthan the rate of withdrawal of the web by said pull-out roll.

8. In a web-treating apparatus, upper and lower series of a plurality ofweb rolls around which a. web is passed up and down and between thesucceeding rolls of each series, feed rolls operable to feed the web tothe first r011 in said lower series at a predetermined rate of speed, apull-out roll operable to draw the web from the last roll in theupperseries, variable speed drive means for said pull-out roll, amovable compensator roll about which the web passes disposed betweensaid feed rolls and the web rolls, control means actuable by saidcompensator roll in response to variadrive each of said lower seriesrolls at a surface I speed slightly greater than the rate of feed of theweb thereto by said feed rolls and greater than the rate oi withdrawalof the web. by said pullout roll.

JOHN J. FRANKIm.

REFERENCES CITED The following references are of record in the flle ofthis patent:

UNI'IED STATES PATEN'I'B Number Name Date 2,135,516 Hurxthal Nov. 8,1938 2,474,717 Belcher June 28, 1949

